Upload
vuphuc
View
222
Download
4
Embed Size (px)
Citation preview
Phase DiagramBi-Sn
By: Seth Van Grinsven Chris Wenrich
ENGR 45Fall 2011
Resistivity vs %wt Concentration
Planned:3 Metals Bi - Sn - Zi20% Intervals (See Right)
21 Total Samples
Make Wire
Measure Resistance
Calculate (ρ)
Bismuth (Wt %) Tin (Wt %) Zinc (Wt %)
100 0 0
0 100 0
0 0 1000 80 200 60 400 40 600 20 8020 80 020 60 2020 40 4020 20 6020 0 8040 60 040 40 2040 20 4040 0 6060 40 060 20 2060 0 4080 20 080 0 20
Making the Wire
Casting Sand Mold:
Place Sand in .40 M tube.
Pack it densely
Insert thin rod through the tube
Pull rod out
Pour molten liquid into mold
Remove sand, Repeat
Machining a Mold:
Use square block of metal
Machine a 1 mm diameter line down the block (.40m)
Screw in a plate to cover moldOpening for liquid
Pour molten liquid into opening
Remove Cover and Wire, Repeat.
Machine Molding
FAILURES SUCCESS
- molten metal had too much surface tension not allowing it to flow into hole. - 1mm slot is too small for metal to be poored into unless pressurized into it. - working mold would not fit in furnace thus heat needed was harder to achieve.
- design works, as proven with water. -if put into larger scale, a much greater chance of success would be achieved. - accurate dimensions because of machined would allow for accurate test results.
MACHINE MOLD DETAILS
Double Kelvin Bridge
Special Wheatstone Bridge used resistances <1 Ohm
Uses ratios of known resistorsand a galvanometer to calculate resistance
Up to 2% accuracy for 1 uOhm.
Problems with Experiment
Both attempts at forming wire -- Failed.
Sand Molding - Liquid Would Seep out of mold.Would absorb particles into mixtureSolidified before reached end of mold
Metal Molding:Molten Metal had strong tension on metal moldingWould not drain into openingWould solidify the opening closed.
Plan Two: Hardness Curve
Expected Curve similar to---------------------------------->(This is solubility of H2 in NickleCopper)
Small Rise when going from oneto other, even though one has much lower value.
Hardness Scales
Scale Indenter Minor Load
Major Load
Total Load
Value of E
A Diamond Cone 10 50 60 100
B 1/16 10 90 100 130C Diamond Cone 10 140 150 100
D Diamond Cone 10 90 100 100
E 1/8 10 90 100 130F 1/16 10 50 60 130
G 1/16 10 140 150 H 1/8 10 50 60 K 1/8 10 140 150 130
L 1/4 10 50 60 130M 1/4 10 90 100 130P 1/4 10 140 130
R 1/2 10 50 130S 1/2 10 90 130V 1/2 0 140 130
HRA . . . . Cemented carbides, thin steel and shallow case hardened steel
HRB . . . . Copper alloys, soft steels, aluminium alloys, malleable irons, etc.HRC . . . . Steel, hard cast irons, case hardened steel and other materials harder than 100 HRBHRD . . . . Thin steel and medium case hardened steel and pearlitic malleable ironHRE . . . . Cast iron, aluminium and magnesium alloys, bearing metalsHRF . . . . Annealed copper alloys, thin soft sheet metalsHRG . . . . Phosphor bronze, beryllium copper, malleable irons HRH . . . . Aluminium, zinc, lead
HRM . . . . . . . . Soft bearing metals, plastics and other very soft materials
Problems with Hardness Testing
We have no 1/4 '' steel ball for rockwell machine at the JC.
The largest diameter indenter with the smallest load we had available to us pushed through metal on setup.
Ultimately the metals were too soft for our available equipment.
No other way for us to measure hardness.
Third Time is the Charm
Phase Diagram of Bi-Sn
PROCDURE- weigh and divide the alloys into test tubes so that their weight percentages match the desired values. - hook up the thermocouple to logger pro and calibrate it in an ice bath so that base temp. is 0 degrees Celsius. - melt each allow into a liquid state and measure the temp. using logger pro until the liquid turns to a solid state and low enough temp. that the phase diagram shows nothing more is going on. - read the graph accordingly to determine the temperatures used for the phase diagram. - repeat with each alloy sample
SETUP
HOW TO READ LOGGER PRO GRAPH
( 1 ) ( 2 )
- in graph (1) the pure form of the metal is measured and only one temperature is taken, at the flat part of the slope. - in graph (2) weight percentage alloys is measured and T1 is the top temp. of the linear slope and T2 is the bottom temp. of the linear slope. - each value represent a point on the phase diagram
10
Sample # Bismuth Tin Sample # Bismuth Tin
1 100 0 1 10 0
2 97.5 2.5 2 9.74 0.25093
3 95 5 3 9.5153 0.4999
4 90 10 4 9.039 1.0065
5 70 30 5 7.0023 2.9719
6 50 50 6 5.0119 5.0162
7 30 70 7 3.018 7.0189
8 10 90 8 1.0171 9.0079
9 5 95 9 0.4925 9.4979
10 2.5 97.5 10 0.2507 9.7545
11 0 0 11 0
Weight Percentages (%) Actual Weight Percentages (grams)
ALLOY PERCENTAGES
( 1 )
( 2 )
( 3 )
( 4 )
( 5 )
( 6 )
LOGGER PRO GRAPHS
( 7 )
( 8 )
( 9 )
( 10 )
( 11 )
LOGGER PRO GRAPHS cont.
Sample # % Tin T1 T2 T3
1 0 270 270
2 2.5 258.3 239.3 130.3
3 5 252.2 137.8
4 10 237.6 139.5
5 30 172.2 140.3
6 50 141.2 136
7 70 198 136.9
8 90 227.3 189.4 104.2
9 95 236.7 203.2 70.6
10 97.5 241 220.4
11 100 241 241
Temperature Readings
PHASE DIAGRAM COMPARISON
Experimental
Theoretical
Potential Error
Unable to get the low T3's due to cooling curve slope being similar to slow of T2-T3 line.Metals may have not mixed 100%, so may have been partial nodes of pure metals. Since weight percentages were such little samples slight miscues in weighing could have a greater effect.
Lack of ideal data points makes graph look funny.
RESOURCES- http://www.springerlink.com/content/t0j7138825ntl830//fulltext.html#Fig1 - people from Agilent Technologies - Younes Ataiiyan
http://www.allaboutcircuits.com/vol_1/chpt_8/10.html
SPECIAL THANKS-Agilent Technologies (machine and design of mold for wire) -Rob Wenrich -Ron Toy -Ryan Basch -Younes Ataiiyan(supervising, masterminding new experiments after failures of old, helping conduct experiment)